4-11 婴儿可以人工培育吗？（在线收听）

Can Babies Be Designed?

We hear a lot nowadays about designer babies. The idea that parents can choose the genes of their children sounds frightening. The question we have to answer is: how much can we and should we control the creation of designer babies?

What exactly is a “designer baby”? One simple way that parents design their child is by choosing its sex. From a technical point of view, this is very easy. In Europe, it is not legal to do this. But in the United States, people can pay about ＄ 2,000 to go to a specialized fertility¹ clinic where they can choose the sex of their child.

It is also possible to choose the specific genes that a baby will have. This happens for medical reasons, to avoid certain serious genetic diseases. A lot of people are worried that parents will want to choose their baby’s genes for non-medical reasons. The parents may, for example, want to have a child with specific qualities. Some experts believe that this will certainly happen. Professor Lee Silver of Princeton University in the USA says, “Men and women will go to specialized clinics. The doctors will take about 200 eggs from the women. The eggs will be fertilized². Then the doctors will choose the embryo³ that has the desired genes. They will throw away the other embryos.”

In this case, the genes of the baby will have come from the parents. But it is also possible to add genes to an embryo. The baby that grows will then have genes that did not come from its parents, for example, a gene for intelligence or for musical ability.

Nobody has added a gene to a human embryo yet, but scientists have added genes to other animals. Dr Keith Campbell is one of the researchers who cloned Dolly, the sheep. Dr Campbell has also added a human gene to another sheep called Polly. Dr Campbell says, “The way of adding genes to humans is the same as in animals.”

If someone tries to add a gene to a human embryo, something terrible could happen. Some of the experiments on animals have in fact produced terrible consequences. In one experiment, scientists added a gene to pigs to make them grow bigger more quickly. But the experiment went wrong -- only some parts of the pigs grew bigger and quickly the animals became ill and died.

The problem is that scientists do not know enough about what specific genes do and how different genes work together. Dr Dean Hamer of the National Cancer Institute says, “One gene can do a lot of different things. We can never be sure that we know everything about a particular gene. If we added a gene to a human, the result could be terrible.”

If scientists add a gene to a human, that new gene will be passed to future generations. After many generations, this could produce a division⁴ in society. Professor Lee Silver says, “The problem with this technology is that it will make a division between rich and poor. The rich will have good genes. They will be intelligent, beautiful and healthy. The poor will have bad genes.”

Dr Hamer is sure that one day scientists really will design human genes. “The question isn’t: will we be able to do it?” he says. “The real question now is: what genes are we going to change?”

注释：

1.fertility [fE:5tiliti] n. [生] 能育性；繁殖力

2.fertilize [5f\:tilaiz] vt. [生] 使受精，使受胎

3.embryo [5embriEu] n. 胚胎

4.division [di5viVEn] n. 分隔；分界；分歧

婴儿可以人工培育吗？

眼下我们听到许多关于人工培育良种婴儿的传闻。这种父母可以为自己的孩子选择基因的想法听上去令人惊恐。我们要回答的问题是：我们能够并应该在多大程度上对婴儿人工培育进行控制呢？

　　到底什么是“人工培育良种婴儿”呢？父母人工培育婴儿的一种简单办法就是选择性别。从技术角度上讲，这是一件很容易做到的事情。在欧洲这样做是非法的，但是在美国，人们可以支付大约2000美元去一个专门的生育诊所，在那里可以对孩子的性别进行选择。

也可以为婴儿挑选特别的基因。这是出于健康考虑，以避免孩子患上某些严重的遗传疾病。很多人担心父母不是出于健康原因去为自己的孩子选择基因。比如，父母可能希望拥有一个具有某种特殊才能的婴儿。有些专家相信这种事情早晚会发生。美国普林斯顿大学李·西尔弗教授说：“男人和女人将前往专门诊所。医生将从妇女体内提取大约200个卵子，使这些卵子受精。然后医生将留下带有父母所希望的基因的那个胚胎，把其他胚胎丢弃。”

　　在这种情况下，婴儿的基因都会来自其父母。但是也有向胚胎中注入其他基因的可能性。这个婴儿长成后于是会有不是来自其父母的基因，如智力基因或者音乐才能基因。

　　到现在还没有任何人向人类胚胎中注入过基因，但是科学家已经给动物注入了基因。基思·坎贝尔博士是进行多莉羊克隆的研究者之一。他还给另一只羊波莉注入了人类基因。他说：“给人注入基因与给动物注入基因的方法是一样的。”

　　如果有人想要向人类胚胎内注入某一基因，那么可怕的事情可能会发生。实际上，一些对动物的试验已经产生了可怕的后果。在一次试验中，科学家给猪注入了某一基因，以促使其长得更大更快。但是试验却出现了问题——猪只是局部长得更大，结果很快便病死了。

　　科学家面临的问题是，他们尚不清楚特种的基因能起什么作用以及不同的基因是如何配合起作用的。全国癌症研究所迪安·哈默博士说：“一个基因可以做许多不同的事情。我们永远也无法确定我们对某一基因已经了如指掌。如果我们给一个人注入某一基因，其结果可能是可怕的。”

　　假若科学家给一个人注入某一基因，那个新基因将会一代代往下遗传。经过若干代，这可能造成社会的差异。李·西尔弗教授说：“这个技术的问题在于，它将在富人与穷人之间形成一条鸿沟。富人将拥有好的基因，他们将变得聪明、漂亮和健康。而穷人将只能有不好的基因。”

　　哈默博士肯定有一天科学家将真正进行人类基因的培育。他说：“问题不在于我们是否有能力去做，而是在于我们将要改变哪些基因。”